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Torch Object Storage

FAQ

Feature FAQ

Category	FAQ
Performance	Does TOS have bandwidth and QPS limits? What are the QPS and bandwidth limits for TOS? Are the upload and download limits independent of each other? How can I test the read/write performance from a client to a TOS server?
Network and protocol	Does TOS support IPv6? Does TOS support regions outside of China? Does TOS support HTTPS access? Does TOS support HTTP/2? Can an ECS instance in one region access a bucket in another region via the private network?
Server-side encryption	How can I tell if an object in a bucket is stored with server-side encryption?
Event notification	Does TOS send notifications for object-related events?
Others	How can I see the daily traffic for a bucket? Can I convert a single-AZ bucket to a multi-AZ bucket? How can I access bucket resources across origins? I get an error saying the domain is not registered when I try to associate a custom domain with a bucket. Why?

Performance

Does TOS have bandwidth and QPS limits?

Yes. For more information, see Constraints and limitations.

What are the QPS and bandwidth limits for TOS? Are the upload and download limits independent of each other?

TOS applies throttling limits to both the account and bucket levels for QPS and bandwidth. The bucket-level limit is no higher than the account-level limit. Different operations, such as uploads, downloads, and listings, have their own independent throttling configurations. For more information, see Constraints and limitations.

Submit a ticket if you need higher QPS or bandwidth.

How can I test the read/write performance from a client to a TOS server?

You can test performance using the following methods:

tip

The following examples measure the rate for a single stream.

Method 1: Use the speed test command (probe) in tosutil. For more information, see Test upload and download speeds (probe).

# 1. Download tosutil
# Linux
wget https://tos-tools.tos-cn-beijing.volces.com/linux/tosutil && chmod a+x tosutil
# macOS
wget https://tos-tools.tos-cn-beijing.volces.com/darwin/tosutil && chmod a+x tosutil
# Windows
wget https://tos-tools.tos-cn-beijing.volces.com/windows/tosutil -O tosutil.exe

# 2. Use the probe command to test upload speed
./tosutil probe

# 3. Use the probe command to test download speed
./tosutil probe -pt download

Method 2: Use the curl command. Example:

# The following commands apply to Linux and macOS. If you are using Windows, open CMD (Command Prompt) and replace /dev/null with NUL in the commands.
# 1. Test download speed
# Test download speed in Beijing
curl -o /dev/null -L "https://probe-bucket-beijing.tos-cn-beijing.volces.com/download/test"
# Test download speed in Shanghai
curl -o /dev/null -L "https://probe-bucket-shanghai.tos-cn-shanghai.volces.com/download/test"
# Test download speed in Guangzhou
curl -o /dev/null -L "https://probe-bucket-guangzhou.tos-cn-guangzhou.volces.com/download/test"

# 2. Test upload speed. Prepare a local file over 100 MB and name it "filename".
# Test upload speed in Beijing
curl -o /dev/null -L "https://probe-bucket-beijing.tos-cn-beijing.volces.com/upload/filename" -F "file=@filename" --request PUT
# Test upload speed in Shanghai
curl -o /dev/null -L "https://probe-bucket-shanghai.tos-cn-shanghai.volces.com/upload/filename" -F "file=@filename" --request PUT
# Test upload speed in Guangzhou
curl -o /dev/null -L "https://probe-bucket-guangzhou.tos-cn-guangzhou.volces.com/upload/filename" -F "file=@filename" --request PUT

Network and protocol

Does TOS support IPv6?

No. If your business requires IPv6, please contact the TOS service team for assistance.

Does TOS support regions outside of China?

Regions outside of China are being prepared. If you need to use TOS outside of China, please contact your account manager. For a list of supported regions, see Regions and endpoints.

Does TOS support HTTPS access?

Yes.

Does TOS support HTTP/2?

No. If your business requires HTTP/2, please contact the TOS service team for assistance.

Can an ECS instance in one region access a bucket in another region via the private network?

No. An ECS instance in one region can only access a bucket in another region via the public network.

Server-side encryption

How can I tell if an object in a bucket is stored with server-side encryption?

You can check the encryption method to see if an object is stored with server-side encryption.

SSE-TOS: If the response header contains x-tos-server-side-encryption when you read the object metadata via HeadObject or the object content via GetObject, the object is encrypted by the server with SSE-TOS.

SSEC: When using HeadObject or GetObject, access must be via HTTPS. To decrypt the source object, the request headers must include x-tos-server-side-encryption-customer-algorithm, x-tos-server-side-encryption-customer-key, and x-tos-server-side-encryption-customer-key-md5. Otherwise, the request will fail.

A successful request will include the response headers x-tos-server-side-encryption-customer-algorithm and x-tos-server-side-encryption-customer-key-MD5. These headers indicate that the object is encrypted by the server with SSEC.

Event notification

Does TOS send notifications for object-related events?

Yes. TOS can deliver notifications for certain changes to objects to Volcano Engine Function as a Service (veFaaS). For more information, see Event notification overview.

warning

veFaaS is currently in closed beta and not generally available. If you would like to try it, please contact your account manager to request trial access. You will then be able to view the relevant documentation and console.

Others

How can I see the daily traffic for a bucket?

Log in to the TOS console. In the top menu bar, select Billing > Order management. In the left navigation pane, click Split bills. On the right, set Period to By day. From the Product drop-down list, select Torch Object Storage. You can then view your bucket's daily traffic data.

Can I convert a single-AZ bucket to a multi-AZ bucket?

You can enable multi-AZ redundancy when creating a bucket or convert an existing single-AZ bucket. For more information, see Changing the redundancy type.

How can I access bucket resources across origins?

You need to configure cross-origin resource sharing (CORS) rules. For more information, see CORS rules.

I get an error saying the domain is not registered when I try to associate a custom domain with a bucket. Why?

This error means that your domain has not been registered yet. You must obtain an Internet Content Provider (ICP) license for your domain before you can associate it with a bucket.

Last updated: 2026.10.14 10:09:58